1. Field of the Invention
This invention relates to a stopper for containers for use in analyses, being particularly useful as a closing and opening member for fluid containing vessels.
The stopper is of the type comprising a resilient body, provided with an internal cavity closed by a transverse wall perforatable by a tubular member adapted for transferring the fluid from the container to the tubular member.
2. Description of the Prior Art
Several devices have been hitherto known comprising a test-tube type container containing 9 fluid or specimen to be analysed or for use in analysis, which comprises a sealing stopper for inserting the fluid in the container or withdrawing it therefrom. The known devices and techniques, while having overcome certain drawbacks, maintain a high contact time of the contained fluid with the ambient air due to the fact that the container has to be opened and closed each time a specimen has to be taken or inserted.
Embodiments are also known comprising essentially a hollow resilient stopper having a perforatable wall, disposed in the container and allowing for the insertion or removal of specimens by a conventional tubular member which tapers slightly at the front end thereof such as a pipette; nevertheless, once the wall has been perforated, it also allows extended contact with the ambient surroundings.